Mono, thanks, that is the one I was after. I tried Rodinal 1+50 once in 16C and was quite happy with the results but the negative side of things is that the development time grows to 20min range. One example is here: .
I haven't tested with 1+25 dilution but I might do that some day.

For stand development in Rodinal 1+100 I still think 14C is doable. The developer will be exhausted which is the main idea, but it just takes some more time. What's really important here is that the outside temperature is about the same with the temperature in the tank so the liquid doesn't move and create uneven skies or stripes so typical for the stand development.